U.S. Pat. No. 4,600,216 of Burkholder, entitled "Vehicle Steering and Suspension System," discloses a three-wheeled vehicle steering and suspension system that includes, inter alia, a pair of bungee cords that resist rotation of the cylindrical tubular housing of a support wheel assembly for each main wheel. The bungee cords are a part of the vehicle's suspension and steering system and work in combination with a pair of shock absorbers to allow for independent suspension of the main wheels.
U.S. Pat. No. 5,054,800 of Christiansen et al., entitled "Bicycle Trailer for Small Children," discloses a bicycle trailer including a frame that is slidably mounted onto a main axle rotatably journaled between the two main wheels of the trailer. A pair of bungee cords are draped over the trailer axle and around a couple of bosses at the lower extremity of the trailer frame. The bungee cords resiliently join the axle to the trailer frame.
The foregoing two patents should be considered in order to put the present invention into a proper perspective. It is an object of the present invention to utilize the advantages achievable with elastic cords, such as Bungee cords, in a suspension system that is self-contained and adapted for a variety of applications.
In one particular application, the present invention is designed to replace a strut-type shock absorber. For vehicles operating in cold weather conditions, oil-filled gas-charged shocks tend to heat up due to internal friction. This frequently occurs when the vehicle moves over rough terrain and at high speeds. The increased heat causes condensation to form on the inside of the cylinder and contaminates the oil with water. The result is a loss of performance from the shock absorber. This is a particular problem for snowmobiles where routine replacement and/or rebuild is required.
Additionally, dirt bikes have gone to much larger cylinder capacity for their shock absorbers. The result is an increase in weight, which is not desirable. The present invention also is designed to address this problem.